1 #! /usr/bin/env python

     2 

     3 class Markov:

     4     def __init__(self, histsize, choice):

     5         self.histsize = histsize

     6         self.choice = choice

     7         self.trans = {}

     8     def add(self, state, next):

     9         if not self.trans.has_key(state):

    10             self.trans[state] = [next]

    11         else:

    12             self.trans[state].append(next)

    13     def put(self, seq):

    14         n = self.histsize

    15         add = self.add

    16         add(None, seq[:0])

    17         for i in range(len(seq)):

    18             add(seq[max(0, i-n):i], seq[i:i+1])

    19         add(seq[len(seq)-n:], None)

    20     def get(self):

    21         choice = self.choice

    22         trans = self.trans

    23         n = self.histsize

    24         seq = choice(trans[None])

    25         while 1:

    26             subseq = seq[max(0, len(seq)-n):]

    27             options = trans[subseq]

    28             next = choice(options)

    29             if not next: break

    30             seq = seq + next

    31         return seq

    32 

    33 def test():

    34     import sys, string, random, getopt

    35     args = sys.argv[1:]

    36     try:

    37         opts, args = getopt.getopt(args, '0123456789cdw')

    38     except getopt.error:

    39         print 'Usage: markov [-#] [-cddqw] [file] ...'

    40         print 'Options:'

    41         print '-#: 1-digit history size (default 2)'

    42         print '-c: characters (default)'

    43         print '-w: words'

    44         print '-d: more debugging output'

    45         print '-q: no debugging output'

    46         print 'Input files (default stdin) are split in paragraphs'

    47         print 'separated blank lines and each paragraph is split'

    48         print 'in words by whitespace, then reconcatenated with'

    49         print 'exactly one space separating words.'

    50         print 'Output consists of paragraphs separated by blank'

    51         print 'lines, where lines are no longer than 72 characters.'

    52     histsize = 2

    53     do_words = 0

    54     debug = 1

    55     for o, a in opts:

    56         if '-0' <= o <= '-9': histsize = eval(o[1:])

    57         if o == '-c': do_words = 0

    58         if o == '-d': debug = debug + 1

    59         if o == '-q': debug = 0

    60         if o == '-w': do_words = 1

    61     if not args: args = ['-']

    62     m = Markov(histsize, random.choice)

    63     try:

    64         for filename in args:

    65             if filename == '-':

    66                 f = sys.stdin

    67                 if f.isatty():

    68                     print 'Sorry, need stdin from file'

    69                     continue

    70             else:

    71                 f = open(filename, 'r')

    72             if debug: print 'processing', filename, '...'

    73             text = f.read()

    74             f.close()

    75             paralist = string.splitfields(text, '\n\n')

    76             for para in paralist:

    77                 if debug > 1: print 'feeding ...'

    78                 words = string.split(para)

    79                 if words:

    80                     if do_words: data = tuple(words)

    81                     else: data = string.joinfields(words, ' ')

    82                     m.put(data)

    83     except KeyboardInterrupt:

    84         print 'Interrupted -- continue with data read so far'

    85     if not m.trans:

    86         print 'No valid input files'

    87         return

    88     if debug: print 'done.'

    89     if debug > 1:

    90         for key in m.trans.keys():

    91             if key is None or len(key) < histsize:

    92                 print repr(key), m.trans[key]

    93         if histsize == 0: print repr(''), m.trans['']

    94         print

    95     while 1:

    96         data = m.get()

    97         if do_words: words = data

    98         else: words = string.split(data)

    99         n = 0

   100         limit = 72

   101         for w in words:

   102             if n + len(w) > limit:

   103                 print

   104                 n = 0

   105             print w,

   106             n = n + len(w) + 1

   107         print

   108         print

   109 

   110 def tuple(list):

   111     if len(list) == 0: return ()

   112     if len(list) == 1: return (list[0],)

   113     i = len(list)//2

   114     return tuple(list[:i]) + tuple(list[i:])

   115 

   116 if __name__ == "__main__":

   117     test()